How To Put Lenovo S-90-A into Diagnostic Mode And Change Imei With NCK QUALCOMM MODULE 0.7:
Power off your phone and hold the Volume Down key while inserting the other end of the USB CABLE into PC
Keep holding without releasing the Volume Down Key until the ENGINEERING MENU appears.
*Check Device Manager to make sure you are on Diag mode, if not found, install phone drivers.
*Once done, you can program your own imei on it.
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